聚合物黏弹性提高驱油效率研究

Research on improving oil displacement efficiency using viscoelastic behavior of polymer

通过室内物理模拟实验,在弱亲油人造物理模型上研究第一法向应力差N1(弹性)、第一法向应力差斜率SN1(弹性)和威森博格数We(弹性)对驱油效率和残余油饱和度的影响。在弱亲油的人造物理模型上研究相同黏度条件下甘油与聚丙烯酰胺(HPAM)的驱油效率,在此基础上,在大庆油田开展两个高浓度聚合物矿场试验。结果表明:随着第一法向应力差、第一法向应力差斜率和威森博格数的增加,驱油效率增加,残余油饱和度降低;具有弹性的聚合物溶液,驱油效率明显高于相同黏度下的甘油;高浓度聚合物所具有的高黏弹性使采收率有较大幅度提高。

Some physical simulation experiments were conducted. The effects of the first normal stress difference N1 , the slope of the first normal stress difference SN1 and Wesson Borg number on oil displacement efficiency and residual oil saturation based on slightly oleophilic artificial physical model were studied. Under the same viscosity conditions, the oil displacement efficiency was investigated. Two high-concentration polymer flooding field tests were carried out in Daqing Oilfield. The results demonstrate that with the increase of the first normal stress difference, the slope of the first normal stress difference and Wesson Borg number, the oil displacement efficiency increases and residual oil saturation decreases. Under the same viscosity conditions, the oil displacement efficiency of polymer flooding was higher than that of the glycerol flooding significantly because of the elasticity of polymer. The oil recovery efficiency is greatly improved because of high viscoelastic behavior of high concentration polymer.